The present invention relates in general to stone cutting saws, and more particularly to the types of saws used in lapidary work for initially cutting a stone into slabs.
Prior art saws of this general nature may be broadly classified as circular type saws and band type saws. Band type saws usually employ an endless and highly tensioned multi-strand wire trained around drive and idler sheaves, and means for applying a liquid and abrasive slurry to the cutting reach of the wire. One of the drawbacks of such cutting wires is that they are relatively expensive. The relatively high expense for such cutting wires is related to their multi-strand and endless construction. This type of construction requires splicing, since it is not practical to use a rigid coupling. Another problem is that of continuously providing and delivering a thoroughly mixed cutting slurry to the cutting reach of the cutting wire, and collecting and returning the slurry to the cutting reach.
The patent to Lansing No. 2,150,381 discloses an endless cutting wire having a horizontal cutting reach which descends vertically through the developing saw kerf and is supplied with a cutting slurry of water and sand delivered by gravity from a slurry tank. The cutting wire construction is not disclosed, nor is there any provision for returning the slurry to the slurry tank.
The U.S. Pat. to Dessureau et al., No. 2,866,448 provides a vertical cutting wire reach which passes downward through a conical cup supplied with abrasive slurry, through the stone being cut, and through a second conical cup which apparently wipes the slurry from the wire to prevent it from interfering with the operation of the sheaves on which is mounted the endless cutting wire. No slurry agitation or recollecting means is disclosed, the thrust of the disclosure being to articulated mounting means which allow the cutting wire to trace any desired profile cut.
Wayland et al., U.S. Pat. No. 2,994,314 discloses a wire-type stone sawing machine having a vertically descending horizontal cutting reach gravitationally supplied with cutting slurry via a nozzle fed from an overhead separation chamber. The separation chamber is associated with somewhat complex means for collecting and recirculating the slurry plus additional fresh water and abrasive particles, and separates the stone particles from the slurry mixture.
Dioguardi, U.S. Pat. No. 3,220,149 discloses a metal cutting machine employing a high tension cutting wire, and which machine includes slurry collecting and recirculating means.
Other patents of interest are:
U.S. Pat. No. 3,311,415
U.S. Pat. No. 3,098,475
U.S. Pat. No. 1,620,021
U.S. Pat. No. 3,028,711
U.S. Pat. No. 3,299,877